The bactericidal mechanism of carbon monoxide (CO) and the feasibility of CO-releasing molecules as anti-infective drugs were summarized by consulting scientific literature, combined with our own research work. Anaerobic bacteria are usually tolerant to high concentration of CO, and some can even grow with CO as sole carbon or energy source, but most pathogenic bacteria are sensitive to CO. In view of the difficulty of gaseous CO in controlling the applying dose and the action site, CO release molecules were synthesized. CO release molecules not only have higher bactericidal activities against common pathogenic bacteria than gaseous CO, but also have the ability to kill antibiotics-resistant bacteria and destroy their biofilms. CO mainly binds with heme-Fe²⁺ in cells, interrupting the electron transfer of respiration chains, which would result in the generation of reactive oxygen species. CO can also disturb intracellular ion balance, which further triggers free radical reactions. Due to its diverse acting targets, uneasy to induce drug resistance, and synergistic effect with other antibiotics, CO is expected to be the next generation of anti-infection drugs.

carbon monoxide  /  carbon monoxide-release molecule  /  heme  /  reactive oxygen species  /  anti-infective drug